Method of treating spontaneously combustible catalysts

ABSTRACT

Self-heating characteristics of a spontaneously combustible catalyst are reduced by treating spontaneously combustible catalysts with oxygen-containing hydrocarbons having at least 12 carbon atoms. The treatment is particularly suitable for reducing the self-heating characteristics of sulfidable metal oxide(s)-containing catalysts, presulfurized catalysts, presulfided catalysts or reduced catalysts. When applied to sulfur-containing catalysts, the treatment gives a catalyst that has suppressed self-heating properties without substantially compromising sulfur retention or activity. Further hydrocracking catalysts treated by the oxygen-containing hydrocarbons give improved product yield. Further, a method of safely unloading a catalyst from a reactor is provided where the catalyst in the reactor is treated with a liquid mixture containing oxygen-containing hydrocarbon having at least 12 carbon atoms to wet the catalyst.

This is a continuation of application Ser. No. 08/307,559 filed Sep. 16,1994, now abandoned which is a continuation-in-part of application Ser.No. 08/057,596, filed May 4, 1993, now abandoned and acontinuation-in-part of application Ser. No. 08/219,163, filed Apr. 1,1994, now abandoned which is a continuation-in-part of application Ser.No. 08/057,596, filed May 4,1993 now abandoned.

FIELD OF THE INVENTION

This invention relates to a method of treating spontaneously combustiblecatalysts and catalyst compositions resulting from such treatment. Inone aspect, the invention relates to a process for preparing catalyststhat produces catalyst compositions with reduced self-heatingcharacteristics. In another aspect, the invention relates tohydrotreating and/or hydrocracking processes.

BACKGROUND OF THE INVENTION

A spontaneously combustible catalyst may be defined as any catalystcomposition which has a tendency to self-heat or combust in the presenceof air or oxygen at a temperature of 200° C. or lower. Particularly manyhydrocarbon processing catalysts, such as hydrotreating, hydrocrackingand tail-gas treating catalysts which typically contain sulfur andreduced catalysts such as hydrogenation catalysts can be classified asspontaneously combustible catalysts. Some of the hydrocarbon processingcatalysts can also be a reduced catalyst.

A hydrotreating catalyst may be defined as any catalyst compositionwhich may be employed to catalyze the hydrogenation of hydrocarbonfeedstocks, and most particularly to hydrogenate particular componentsof the feed stock, such as sulfur-, nitrogen- and metals-containingorgano-compounds and unsaturates. A hydrocracking catalyst may bedefined as any catalyst composition which may be employed to crack largeand complex petroleum derived molecules to attain smaller molecules withthe concomitant addition of hydrogen to the molecules. Suchhydrocracking catalyst includes catalysts used for residue conversionunits. A tail gas catalyst may be defined as any catalyst which may beemployed to catalyze the conversion of hazardous effluent gas streams toless harmful products, and most particularly to convert oxides of sulfurto hydrogen sulfide which can be recovered and readily converted toelemental sulfur. A reduced catalyst may be defined as any catalyst thatcontains a metal in the reduced state such as an olefin hydrogenationcatalyst. Such metals are typically reduced with a reducing agent suchas, for example, hydrogen or formic acid. The metals on these reducedcatalyst may be fully reduced or partially reduced.

Catalyst compositions for hydrogenation catalysts are well known andseveral are commercially available. Typically, the active phase of thecatalyst is base on at least one metal of group VIII, VIB, IVB, IIB orIB of the periodic table. In general, the hydrogenation catalystscontains at least one element selected from Pt, Pd, Ru, Ir, Rh, Os, Fe,Co, Ni, Cu, Mo, W, Ti Hg, Ag or Au supported usually on a support suchas alumina, silica, silica-alumina and carbon. Such reduced catalystscan be classified as spontaneously combustible substances.

Catalyst compositions for hydrotreating and/or hydrocracking or tail gastreating are well known and several are commercially available. Metaloxide catalysts which come within this definition includecobalt-molybdenum, nickel-tungsten, and nickel-molybdenum supportedusually on alumina, silica and/or silica-alumina, including zeolite,carriers. Also, other transition metal element catalysts may be employedfor these purposes. In general, catalysts containing at least oneelement selected from V, Cr, Mn, Re, Co, Ni, Cu, Zn, Mo, W, Rh, Ru, Os,Ir, Pd, Pt, Ag, Au, Cd, Sn, Sb, Bi and Te have been disclosed assuitable for these purposes.

For maximum effectiveness the metal oxide catalysts are converted atleast in part to metal sulfides. The metal oxide catalysts can besulfide in the reactor by contact at elevated temperatures with hydrogensulfide or a sulfur-containing oil or feed stock ("in-situ").

However, it is advantageous to the user to be supplied with metal oxidecatalysts having sulfur, as an element or in the form of anorgano-sulfur compound, incorporated therein. These presulfurizedcatalysts can be loaded into a reactor and brought up to reactionconditions in the presence of hydrogen causing the sulfur or sulfurcompound to react with hydrogen and the metal oxides thereby convertingthem into sulfides without any additional process steps being needed.These presulfurized catalysts provide an economic advantage to the plantoperator and avoid many of the hazards such as flammability andtoxicity, which the plant operator encounter when using hydrogensulfide, liquid sulfides, polysulfides and/or mercaptans to sulfide thecatalysts.

Several methods of presulfurizing metal oxide catalysts are known.Hydrotreating catalysts have been presulfurized by incorporating sulfurcompounds into a porous catalyst prior to hydrotreating a hydrocarbonfeedstock. For example, U.S. Pat. No. 4,530,917 discloses a method ofpresulfurizing a hydrotreating catalyst with organic polysulfides. U.S.Pat. No. 4,177,136 discloses a method of presulfurizing a catalyst bytreating the catalyst with elemental sulfur. Hydrogen is then used as areducing agent to convert the elemental sulfur to hydrogen sulfide insitu. U.S. Pat. No. 4,089,930 discloses the pretreatment of a catalystwith elemental sulfur in the presence of hydrogen. U.S. Pat. No.4,943,547 discloses a method of presulfurizing a hydrotreating catalystby subliming elemental sulfur into the pores of the catalyst thenheating the sulfur-catalyst mixture to a temperature above the meltingpoint of sulfur in the presence of hydrogen. The catalyst is activatedwith hydrogen. PCT specification WO93/02793 discloses a method ofpresulfurizing a catalyst where elemental sulfur is incorporated in aporous catalyst and at the same time or subsequently treating thecatalyst with a liquid olefinic hydrocarbon.

However, these ex-situ presulfurized catalysts must be transported tothe user or plant operator. In transportation or shipping, thesepresulfurized catalysts are classified as spontaneously combustiblesubstances which are further classified into two sub-groups of material,pyrophoric substances or self-heating substances. Both groups have thesame basic properties of self-heating which may lead to spontaneouscombustion, but differ in the degree of spontaneous combustion.Pyrophoric substances ignite, even in small quantities, within fiveminutes of coming into contact with air whereas self-heating substancesignite in air only when in large quantities and after long periods oftime. Pyrophoric substances are typically classified as Division 4.2Packing Group I and self-heating substances are classified in eitherPacking Group II or Packing Group III according to the test proceduresrecommended in the Dangerous Goods Special Bulletin, April 1987,published by TDG Ottawa, Transport Canada for Class 4, Division 4.2.These spontaneously combustible substances must be packaged in an UnitedNations (UN) designated 250 kg metal drum or in a smaller package of 100kg plastic fiber drum or even smaller.

It is desirable to transport these presulfurized catalysts in largerquantities such as in flow bins or super sacks for economic reasons andease of handling. But, in order to transport such catalysts in suchlarger quantities safely, they must pass the test for spontaneouslycombustible substances.

Further, some of the prior art ex-situ methods of presulfurizingsupported metal oxide catalysts have suffered from excessive strippingof sulfur upon start-up of a hydrotreating reactor in the presence of ahydrocarbon feedstock. As a result of sulfur stripping, a decrease incatalyst activity or stability is observed. Further, the stripping ofsulfur can cause fouling of downstream equipment.

Therefore, it is an object of the present invention to treatspontaneously combustible catalysts in a manner to suppress theself-heating properties of the catalysts. It is another object of thepresent invention to prepare an air and/or oxygen stable, presulfurizedor presulfided catalyst, either fresh or regenerated with minimalstripping of sulfur and/or decrease in catalyst activity. It is yetanother object of the present invention to provide presulfurizedhydrotreating, hydrocracking and/or tail gas treating catalysts withimproved selectivity and/or activity.

SUMMARY OF THE INVENTION

The present invention provides a composition comprising a spontaneouslycombustible catalyst having at least a portion of said spontaneouslycombustible catalyst coated with a substance comprising at least oneoxygen-containing hydrocarbon having at least 12 carbon atoms bycontacting the spontaneously combustible catalyst with anoxygen-containing hydrocarbon having at least 12 carbon atoms at atemperature of at least 0° C. Such composition has a reducedself-heating characteristic when compared to the spontaneouslycombustible catalyst which has not been coated.

Further, the present invention relates to an improved method ofpresulfurizing a sulfidable metal oxide(s)-containing catalyst whichsuppresses self-heating characteristics of the catalysts. According tothe invention, there is provided a method of presulfurizing porousparticles of a sulfidable catalyst containing at least one metal ormetal oxide, which comprises:

(a) contacting said catalyst with elemental sulfur, a sulfur compound ora mixture thereof at a temperature such that at least a portion of saidsulfur or sulfur compound is incorporated in the pores of said catalystby impregnation, sublimation and/or melting; and

(b) prior to, at the same time or subsequently contacting said catalystparticles in the presence of an oxygen-containing hydrocarbon having atleast 12 carbon atoms.

The method is particularly suitable for application to hydrotreatingand/or hydrocracking or tail gas treating catalysts. In particular, thepresent invention provides an improved catalyst for hydrocrackinghydrocarbon streams.

Further more, the present invention provides a method of unloading acatalyst during a halt in the operation of the reactor wherein thecatalyst in the reactor is contacted with a mixture comprising anoxygen-containing hydrocarbon having at least 12 carbon atoms prior tounloading.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that by treating a spontaneously combustible catalystby contacting with an oxygen-containing hydrocarbon having at least 12carbon atoms, preferably at least 16 carbon atoms, more preferably atleast 20 carbon atoms, the resulting catalyst has suppressedself-heating characteristics when compared to the spontaneouslycombustible catalyst without the treatment. In general, the inventiveprocess suppresses the self-heating properties of the catalysts so theyare no longer classified as spontaneously combustible substances. Thus,the inventive process allows the spontaneously combustible catalysts tobe transported or shipped in any suitable packaging such as flow-bins,super-sacks, or sling-bins for example.

For the purpose of definition, "spontaneously combustible catalyst(s)"is any heterogeneous or solid metal(s)-, metal oxide(s)-, metalsulfide(s)- or other metal compound(s)-containing catalyst which may ormay not be on a support and can be classified as spontaneouslycombustible substances according to the test procedures recommended inthe Dangerous Goods Special Bulletin, April 1987, published by TDGOttawa, Transport Canada for Class 4, Division 4.2 or has a onset ofexotherm below 200° C. as measured by the self-heating ramp testdescribed below in the Illustrative Embodiments. The terms "metal(s)-","metal oxide(s)-" and "metal sulfide(s)-" containing catalysts includecatalyst precursors that are used as actual catalysts after furthertreatment or activation. Further, the term "metal(s)" includes metal(s)in partially oxidized form. The term "metal oxide(s)" includes metaloxide(s) in partially reduced form. The term "metal sulfide(s)" includesmetal sulfide(s) that are partially sulfided as well as totally sulfidedmetals. The above terms include in part other components such ascarbides, borides, nitrides, oxyhalides, alkoxides and alcoholates.

In one embodiment of the present invention, a spontaneously combustiblecatalyst is contacted with at least one oxo-organic composition,material, or substance (one or more oxygen-containing hydrocarbons) at atemperature of at least about 0° C., preferably at least about 15° C. toabout 350° C., more preferably from about 20° C. to about 150° C. Uponcontact, the oxygen-containing hydrocarbon is impregnated into thespontaneously combustible catalyst; the surface of the catalyst iscoated with the oxygen-containing hydrocarbon. For the purpose ofdefinition, the surface of the catalyst include the external surface ofthe catalyst as well as the internal pore surfaces of the catalyst. Theword "coating" or "coated" does not rule out some reaction as definedbelow.

The mechanism by which the oxygen-containing hydrocarbon suppresses theself-heating characteristics or properties of the spontaneouslycombustible catalysts when contacted is not known and will be referencedherein as "reaction" or "reacts" for lack of better terminology. Thesuppressed self-heating result can be readily determined without undueexperimentation by measuring the exothermic onset temperatures for aspecific rising temperature profile of catalysts subjected to differingtemperature/time treatments with the oxygen-containing hydrocarbon andwithout the oxygen-containing hydrocarbon. A suitable method fordetermining the exothermic onset temperatures of the catalysts isdescribed in the Illustrative Embodiment below.

When applied to sulfur-containing catalysts such as sulfided,presulfurized or presulfidable metal or metal oxide catalysts, thetreatment provides a catalyst with suppressed self-heatingcharacteristics without substantially compromising sulfur retention oractivity. The sulfided catalysts can be catalysts sulfided by an in-situpresulfiding method or an ex-situ presulfiding or presulfurizing method.The sulfided, presulfurized or presulfidable metal or metal oxidecatalysts can be fresh or oxy-regenerated. For example, theoxygen-containing hydrogen can be coated on any of the sulfur-containingcatalysts such as disclosed in U.S. Pat. Nos. 4,530,917; 4,177,136;4,089,930; 5,153,163; 5,139,983; 5,169,819; 4,530,917; 4,943,547 and inPCT specification WO93/02793.

The oxygen-containing hydrocarbon can be coated on a reducedhydrogenation catalyst such as disclosed in U.S. Pat. No. 5,032,565.

In another embodiment of the present invention, a presulfidable metal-or metal oxide-containing catalyst is contacted with anoxygen-containing hydrocarbon having at least 12 carbon atoms, prior to,at the same time or subsequent to presulfurizing the presulfidable metalor metal oxide catalysts at a temperature and for a time effective tocause the catalysts to exhibit suppressed self-heating propertiescompared to catalysts without treatment with the oxygen-containinghydrocarbon. Preferably the catalyst is heated after contacting withelemental sulfur or a sulfur compound at an elevated temperature andtimes sufficient to fix the sulfur onto the catalyst. Such heatingprocess can be before or after treatment with the oxygen-containinghydrocarbon.

The mechanism by which the oxygen-containing hydrocarbon suppressesself-heating characteristics of the sulfur-incorporated catalyst whencontacted is not known and will be referenced herein as "reaction" or"reacts" for lack of better terminology. The suppressed self-heatingresult can be readily determined without undue experimentation bymeasuring the exothermic onset temperatures in a manner described below.

Generally, the oxygen-containing hydrocarbon treated catalysts of thepresent invention also have enhanced resistance to sulfur strippingduring startup in a hydrotreating and/or hydrocracking reactor in thepresence of a hydrocarbon feedstock. The mechanism by which thecontacting of the sulfur-incorporated catalyst becomes more resistant tosulfur stripping upon contact with the oxygen-containing hydrocarbons isalso not known and will be referenced herein as "reaction" or "reacts".The enhanced resistance to sulfur stripping can readily be determinedwithout undue experimentation by measuring the resistance to sulfurstripping of catalysts subjected to differing temperature/timetreatments with the oxygen-containing hydrocarbon and without theoxygen-containing hydrocarbon and measuring the resistance to sulfurstripping of the resulting catalysts. A suitable method for determiningsulfur stripping resistance is described in the Illustrative Embodimentbelow wherein toluene is used as a stripping agent.

Further, for elemental sulfur-incorporated catalysts, the percentretention of sulfur is improved by treating the catalyst with theoxygen-containing hydrocarbon, particularly for some high-pore volumecatalysts. The mechanism by which the contacting of the elementalsulfur-incorporated catalyst improves sulfur retention upon contact withthe oxygen-containing hydrocarbons is also not known and will bereferenced herein as "reaction" or "reacts" for lack of betterterminology. The improved sulfur retention can readily be determinedwithout undue experimentation by measuring the percent sulfur retainedcompared with the theoretical amount as described in the IllustrativeEmbodiment below.

The catalysts referred to herein as "sulfidable metal oxide catalyst(s)"can be catalyst precursors that are used as actual catalysts while inthe sulfided form and not in the oxide form. While reference is made tometal oxide catalyst(s), it is understood that while the normal catalystpreparative techniques will produce metal oxide(s), it is possible toutilize special preparative techniques to produce the catalytic metalsin a reduced form, such as the zero valent state. Since metals in thezero valent state will be sulfided as well as the oxides when subjectedto sulfiding conditions, catalysts containing such sulfidable metalseven in reduced or zero valent states will be considered for thepurposes of this invention as sulfidable metal oxide catalyst(s).Further, since the preparative technique of the instant invention can beapplied to regenerated catalysts which may have the metal sulfide notcompletely converted to the oxides, "sulfidable metal oxide catalyst(s)"also refers to these catalysts which have part of their metals in thesulfided state.

There are three general methods used to carry out the process of thisembodiment of the instant invention although other more or lessequivalent methods will occur to one skilled in the art and are intendedto be included within the scope of the invention.

In the first method of the present embodiment porous catalyst particlesare contacted with elemental sulfur or sulfur compounds or mixturesthereof under conditions which cause the sulfur or sulfur compounds tobe incorporated into the pores of the catalyst by impregnation, bysublimation, by melting or by a combination thereof. The elementalsulfur-incorporated or sulfur compound-incorporated catalysts will bereferred to as "sulfur-incorporated catalysts."

The sulfur-incorporated catalyst particles are contacted with anoxygen-containing hydrocarbon having at least 12 carbon atoms attemperatures and times sufficient to cause the sulfur-incorporatedcatalyst particles to exhibit suppressed self-heating propertiescompared to catalysts without treatment with oxygen-containinghydrocarbons.

When elemental sulfur is used as the source of sulfur for the metal ormetal oxide, at least one porous sulfidable metal oxide-containingcatalyst is contacted with elemental sulfur at a temperature such thatthe elemental sulfur is substantially incorporated in the pores of thecatalyst by sublimation and/or melting. When the porous catalystparticle is contacted with elemental sulfur, the temperature should besuch that the sulfur is incorporated into the catalyst by sublimationand/or melting. While the catalyst particles can be contacted withsulfur in the molten state, it is preferred to first admix the catalystparticles with powdered elemental sulfur and then heat the mixture toabove the temperature at which sublimation of the sulfur occurs.

Generally the catalyst particles are heated in the presence of thepowdered elemental sulfur at a temperature greater than about 80° C.Typically the catalyst and powdered sulfur are placed in a vibratory orrotary mixer and heated to the desired temperature for sufficient timeto allow the sulfur to be incorporated into the pores of the catalyst.Times typically will range from about 0.1 hour to about 10 hours orlonger.

Preferably the sulfur impregnation step will be carried out at atemperature ranging from about 90° C. to about 130° C. or higher, up tothe boiling point of sulfur of about 445° C. The lower temperature limitis fixed by the sublimation/melting characteristics of sulfur under thespecific conditions of impregnation, whereas the upper temperature limitis fixed primarily by economics, higher temperatures being more costlyto produce as well as more difficult to work with.

The sulfur-incorporated catalyst is then treated with theoxygen-containing hydrocarbon. The catalyst is preferably contacted at atemperature above about 0° C., preferably at a temperature within therange of from about 15° C. to about 350° C., more preferably from about20° C. to about 150° C. When the oxygen-containing hydrocarbon is liquidor semi-fluid at ambient temperature, it is preferred to contact theoxygen-containing hydrocarbon at ambient temperature for ease ofhandling. If the oxygen-containing hydrocarbon is solid or semi-solid atambient temperature or room temperature, the oxygen-containinghydrocarbon should be contacted with the catalyst at a temperature wherethe solid or semi-solid compound becomes liquid or semi-fluid to enablethe oxygen-containing hydrocarbon to coat and/or impregnate thecatalyst. For the treated catalyst to flow freely for convenience ofhandling, the amount of oxygen-containing catalyst contacted ispreferably less than 100 percent, preferably form about 50 percent to 95percent, more preferably 70 to 90 percent of the remaining pore volumeafter sulfur incorporation, although greater than 100 percent ofoxygen-containing hydrocarbon can be used.

The sulfur-incorporated catalyst may be further heated before and/orafter the oxygen-containing hydrocarbon treatment at a temperaturegreater than about 150° C., preferably at a temperature within the rangeof from about 175° C. to about 350° C. and more preferably from about200° C. to about 325° C. to fix the incorporated-sulfur onto thecatalyst.

Preferred sulfur compounds includes for example, ammonium sulfide,organic mono-, di- and poly-sulfides, dialkyl sulfoxides and anycompounds derived from these compounds upon heating or reductiontreatment in the presence of the sulfidable metal oxide and mixturesthereof. Some examples of organic sulfides include, polysulfides ofgeneral formula R--S(n)--R' or HO--R--S(n)--R--OH wherein n is aninteger from 3 to 20 and R and R' are independently organic radicals of1 to 50 carbon atoms such as ditert dodecyl polysulfide and diethanoldisulfide; mercapto alcohols such as 2-mercaptoethanol; alkylmercaptanssuch as n-butyl mercaptan; thioglycols such as dithiopropyleneglycol;dialkyl or diary sulfides such as di-n-butyl sulfides and diphenylsulfides; dialkylsulfoxides such as dimethyl sulfoxide; and mixturesthereof.

When sulfur compounds are used as the source of sulfur for the metal ormetal oxide, the sulfur compounds are typically impregnated with anaqueous or organic solution. The organic solution can be any hydrocarbonor non-hydrocarbons equivalent to light gasoline, hexanes or gasoline ofwhite spirit type. Such impregnation method by sulfur compounds areknown and described in U.S. Pat. Nos. 5,153,163; 5,139,983; 5,169,819;and 4,530,917. These sulfur-compound incorporated catalysts aretypically reduced by hydrogen, or other organic reducing agents such asformic acid, methyl formate, ethyl formate, acetaldehyde and methylalcohol for example. The sulfur compound-incorporated catalyst istreated with the oxygen-containing hydrocarbon before and/or after thereduction step at the conditions as described above for the elementalsulfur-incorporated catalyst.

In the second method, a porous sulfidable metal oxide-containingcatalyst is contacted with a mixture of powdered elemental sulfur and/ora sulfur compound and an oxygen-containing hydrocarbon having at least12 carbon atoms and preferably while heating the resultant mixture to atemperature above about 80° C.

In the second embodiment according to the present invention, thecatalyst particles are contacted with both the elemental sulfur,preferably powdered, and/or at least one sulfur compound and theoxygen-containing hydrocarbon simultaneously. Other hydrocarbons such asolefins can be optionally added simultaneously. According to thismethod, a mixture of powdered elemental sulfur and/or sulfur compoundand oxygen-containing hydrocarbon is first produced. When elementalsulfur is used as the source of sulfur, a ratio of hydrocarbon to sulfurby weight ranging from about 1:2 to about 30:1 is suitable, with about1:1 to about 6:1 being a preferred ratio. The mixture may be heated topromote homogenous mixing of the components, particularly if theoxygen-containing hydrocarbon is not liquid at ambient conditions or themixture may be a suspension. Toluene or other light weight hydrocarbonsolvents may be added to decrease the viscosity of the mixture. Also,increased heat will achieve the same effect. When a sulfur compound isused as the source of sulfur, a ratio of hydrocarbon to sulfur compoundby weight ranging from about 1:2 to about 30:1 is suitable. The mixtureis then added to a preweighed catalyst sample and mixed. When a mixtureof elemental sulfur and sulfur compound is used as the source of sulfur,a ratio of hydrocarbon to elemental sulfur and sulfur compound by weightranging from about 1:2 to about 30:1 is suitable.

When, elemental sulfur is used or a mixture containing elemental sulfur(can include sulfur compounds) is used, the mixture is then heated toincorporate sulfur at a temperature of above about 80° C. The times andtemperature are the same as in the above described two-step firstembodiment described above, that is from about 0.1 to about 10 hours orlonger. When sulfur compounds are used, the catalyst is subjected toreducing conditions as above for the first embodiment of the invention.

In the third method, a porous sulfidable metal oxide-containing catalystis first contacted with an oxygen-containing hydrocarbon having at least12 carbon atoms before the presulfurization step. The resultant mixturecan be optionally heated to a temperature above about room temperature(i.e. about 25° C.) for a solid or semi-solid hydrocarbon to allow theoxygen-containing hydrocarbon to impregnate the catalyst. The catalystand/or oxygen-containing hydrocarbon is preferably heated to at least atemperature where the oxygen-containing hydrocarbon becomes liquid (e.g.at melting point) or semi-fluid. The oxygen-containing hydrocarbontreated catalyst is then presulfurized by contacting theoxygen-containing hydrocarbon-incorporated catalyst with elementalsulfur and/or sulfur compounds under conditions which cause the sulfuror sulfur compounds to be incorporated into the pores of the catalyst byimpregnation, by sublimation, by melting or by a combination thereof asdescribed in the first method of this embodiment. Optionally, thehydrocarbon-treated presulfurized catalyst can be heated during thesulfurization step or after impregnation of sulfur compounds regardlessof prior heat-treatment. For the process of this invention, the catalystshould preferably be heated at some point after contacting with thesulfur at a temperature above about 150° C. for a time sufficient to fixthe sulfur on the catalyst.

The catalyst is preferably treated with the oxygen-containinghydrocarbon after sulfur and/or sulfur compound incorporation forsuperior suppression of self-heating characteristics. If the sulfurand/or sulfur compound and the oxygen-containing hydrocarbon arecontacted with the metal or metal oxide(s) catalyst simultaneously, itis preferable that the catalyst is contacted in such a manner whichallows the sulfur and/or sulfur compounds to be incorporated orimpregnated into the pores of the catalyst prior to the catalystreacting or being coated with the oxygen-containing hydrocarbon at atemperature of above 80° C.

In any of the above methods of the present embodiment, the amounts ofsulfur or sulfur compounds used in the instant process will depend uponthe amounts of catalytic metal present in the catalyst that needs to beconverted to the sulfide. Typically the amount of sulfur or sulfurcompound used is determined on the basis of the stoichiometric amount ofsulfur or sulfur compounds required to convert all of the metal on thecatalyst to the sulfide form. For example a catalyst containingmolybdenum would require two moles of sulfur or mono-sulfur compounds toconvert each mole of molybdenum to molybdenum disulfide, with similardeterminations being made for other metals. On regenerated catalysts,existing sulfur levels may be factored into the calculations for theamounts of elemental sulfur required.

It has been found that the addition of presulfurizing sulfur (elementalsulfur or sulfur compounds) in amounts down to about 50 percent of thestoichiometric requirement results in catalysts having enhancedhydrodenitrification activity, which is an important property ofhydrotreating and first stage hydrocracking catalysts. Thus, the amountof presulfurizing sulfur used for incorporation into the catalyst willtypically range from about 0.2 to about 1.5 times the stoichiometricamount, and preferably from about 0.4 to about 1.2 times thestoichiometric amount.

For hydrotreating/hydrocracking and tail gas treating catalystscontaining Group VIB and/or Group VIII metals the amount ofpresulfurizing sulfur employed is typically about 2% to about 15% byweight of the catalyst charged, and most preferably, the amount ofpresulfurizing sulfur employed is about 6% to about 12% by weight of thecatalyst charged. It is preferred not to add so much sulfur or sulfurcompounds to the catalyst that the pores are completely filled up. Byleaving residual pore volume, the oxygen-containing hydrocarbons canpenetrate the pores and react therein.

The key step to the instant invention is to contact the catalyst with anoxygen-containing hydrocarbon having at least 12 carbon atoms for asufficient time such that the hydrocarbon impregnates (or reacts) withthe catalyst and provides a sulfurized catalyst that is lessspontaneously combustible and is more resistant to sulfur leaching thanone not contacted with an oxygen-containing hydrocarbon. Typically thecontact temperature is greater than about 0° C. and typically will rangefrom about 15° C. to about 350° C., preferably from about 20° C. toabout 150° C. The contact temperature will vary depending on the meltingpoint or sublimation temperature of the oxygen-containing hydrocarbon.For example, when the oxygen-containing hydrocarbon is a solid or asemi-solid such as lard, the oxygen-containing hydrocarbon processtemperature should preferably be at least at a temperature of themelting point of the solid or semi-solid for a time sufficient for thecatalyst to flow freely (appear "dry" and not stick or clump). In aspecific example of lard as the oxygen-containing hydrocarbon, the lardis preferably contacted at a initial temperature of about 80° C. Theprocess temperature for contacting the oxygen-containing hydrocarbon andcatalyst can be readily determined by the melting point of the solid orsemi-solid at a given pressure environment or visually by checking ifthe oxygen-containing hydrocarbon flows. Contact times will depend ontemperature and the viscosity of the oxygen-containing hydrocarbon,higher temperatures requiring shorter times and higher viscosityrequiring longer times. In general times will range from about 2 minutesto about 2 hours, although longer contact times can also be used.

Preferably the oxygen-containing hydrocarbon is sufficiently flowable orsublimable to give a sufficient contact with the metal oxide catalyst.An oxygen-containing hydrocarbon which is liquid at the elevatedtemperature of contact is more preferred for ease of handling. It ispreferred that the oxygen-containing hydrocarbon is a higherhydrocarbon, i.e., one having a carbon number greater than twelve,preferably greater than sixteen, more preferably greater than twenty.The upper carbon number of useful oxygen-containing hydrocarbon isdetermined by the melting point, solidification point, or smoke point ofthe oxygen-containing hydrocarbon in question. While solid fattyoxygen-containing hydrocarbon having carbon numbers greater than 100 canbe used, they are inconvenient since they must be heated to such a hightemperature in order to be converted into a liquid, although they can beused with a solvent to put them in liquid form. Oxygen-containinghydrocarbons with carbon numbers within the range from about 12 to about100, preferably from about 16 to about 80 are found most useful.

The term "oxygen-containing hydrocarbon" as used herein refers tohydrocarbon molecules containing at least one oxygen atom, whichincludes, for example, acids, acid esters, alcohols, aldehydes, ketonesand ethers. The oxygen-containing hydrocarbon may be mixtures such asacid esters and alcohols, different acid esters and the like. Theoxygen-containing hydrocarbon can be primary, secondary or tertiary. Thehydrocarbon moiety can be straight or branched chain carbon atomlinkages, cyclic, acyclic or aromatic. The hydrocarbon moiety canfurther be saturated or unsaturated. Preferably, the hydrocarbon moietycontains at least some unsaturation for superior activity when appliedto hydrotreating, hydrocracking or tail gas treating catalyst. The term"unsaturated" as used herein refers to hydrocarbon molecules containingat least one carbon-carbon double bond in a molecule or compound(s)containing some carbon-carbon double bond and will have an iodine valueof above 60 measured by standard iodine measuring techniques such asAmerican Oil Chemist Society (AOCS) Official Method Cd 1-25 or IUPACMethod 2.205 described in International Union of Pure and AppliedChemistry, 7th ed., Blackwell Scientific Publications 1987 or any otherstandard iodine measuring techniques. The term "saturated" as usedherein refers to oxygen-containing hydrocarbon compounds containing nocarbon-carbon double bonds or compound(s) containing minimalcarbon-carbon double bonds and have a iodine value of less than 60measured by AOCS Official Method Cd 1-25, IUPAC Method 2.205 or anyother standard iodine measuring techniques.

Preferably oxygen-containing hydrocarbons include, for example, higheralcohols having at least 12, preferably 16, more preferably 20 carbonatoms such as dodecanol, hexadecanol, farnesol, hexestrol, oleylalcohol, cetyl alcohol, hexacosanol, triacontanol, cocceryl alcohol andoctacosanol; higher ethers having at least 12, preferably 16, morepreferably 20 carbon atoms such as dicetyl ether; higher ketones havingat least 12 carbon atoms, preferably 16 carbon atoms, more preferably 20carbon atoms such as palmitone, 10-hydroxypalmitone and 3-octadecanone;higher aldehydes having at least 12 carbon atoms, preferably 16, morepreferably 20 carbon atoms such as palmitaldehyde and olealdehyde;higher acids having at least 12, preferably 16, more preferably 20carbon atoms such as saturated acids such as lauric, myristic, palmitic,stearic, and docosanoic acids for example, or unsaturated higher acidssuch as palmitoleic, oleic, linoleic, linolenic, eleostearic,ricinoleic, eicosenoic, docosenoic, eicosatetraenoic, eicosapentaenoic,decosapentaenoic and docosahexaenoic; higher acid esters having at least12, preferably 16, more preferably 20 carbon atoms including mono-, di-,tri- and poly-fatty acid esters including alkyl and aryl esters of theabove acids (e.g. benzyl oleate and butyl oleate) and esters of theabove acids with mono-glyceride, di-glycerides and triglycerides andmixtures thereof. These glyceride fatty acid esters having from 16 to100, more preferably 18 to 90, most preferably 20 to 80 carbon atoms arepreferred.

Some examples of commercial glyceride fatty acid esters include soybeanoil, linseed oil, safflower oil, corn oil, sunflower oil, cottonseedoil, olive oil, tung oil, castor oil, rapeseed oil, tall oil, peanutoil, coconut oil, palm oil, canbra oil, perilla oil, lard, tallow,marine fat or oil such as fish fat or oil (e.g. herring and sardine),vegetable residues and mixtures thereof. Some examples of commercialhigher alcohols includes alkanol mixtures such as NEODOL® alcohols fromShell Chemical Company, including mixtures of C₉,C₁₀ and C₁₁ alkanols(NEODOL® 91 Alcohol), mixtures of C₁₂ and C₁₃ alkanols (NEODOL® 23Alcohol), mixtures of C₁₂, C₁₃, C₁₄ and C₁₅ alkanols (NEODOL® 25Alcohol), and mixtures of C₁₄ and C₁₅ alkanols (NEODOL® 45 Alcohol); theALFOL® Alcohols from Vista Chemical Company, including mixtures of C₁₀and C₁₂ alkanols (ALFOL® 1012 Alcohol), mixtures of C₁₂ and C₁₄ alkanols(ALFOL® 1214 Alcohol), mixtures of C₁₆ and C₁₈ alkanols (ALFOL® 1618Alcohol) and mixtures of C₁₆, C₁₈, and C₂₀ alkanols (ALFOL® 1620Alcohol); the EPAL® Alcohols from Ethyl Chemical Company, includingmixtures of C₁₀ and C₁₂ alkanols (EPAL® 1012 Alcohol), mixtures of C₁₂and C₁₄ alkanols (EPAL® 1214 Alcohol) and mixtures of C₁₄, C₁₆, and C₁₈alkanols (EPAL® 1418 Alcohol); and the TERGITOL-® Alcohols from UnionCarbide Corporation, including mixtures of C₁₂, C₁₃, C₁₄ and C₁₅alkanols (TERGITOL-L® 125 Alcohols). Suitable commercially availablealkanols prepared by the reduction of naturally occurring fatty acidesters includes for example, the CO and TA products of Procter andGamble Company and the TA alcohols of Ashland Oil Company. Higheroligomers and polymers of polyols such as alkylene glycols are alsosuitable as higher alcohols.

Optionally, these oxygen-containing hydrocarbon treated catalyst can befurther treated with or simultaneously treated with or treated prior tothe hydrocarbon treatment with olefins to enhance catalytic activity inhydrocracking, hydrotreating or tail gas treating. The term "olefin" asused herein refers to hydrocarbons containing at least one carbon-carbondouble bond. The olefins may be monoolefins or polyolefins, cyclic oracyclic, linear or branched. Non-limiting examples of monoolefinsinclude decene, undecene, dodecene, tridecene, tetradecene, pentadecene,hexadecene, heptadecene, octadecene, nonadecene, eicosene, and the like,whether branched, linear or cyclic, alpha or internal olefin. Similarmaterials in the form of di-, tri- and polyolefins may be used.Polycyclic olefins and polyolefins may also be used. The readilyavailable compound dicyclopentadiene is found useful. Theoxygen-containing hydrocarbons may also be admixed with otherhydrocarbons, such as alkanes or aromatic solvents.

In general, for superior activity of the catalyst upon start-up in theplant, the weight percent of the unsaturated compounds of anyhydrocarbon used in the process (include unsaturated oxygen-containinghydrocarbon and olefins) of the instant invention should be above about5% wt., preferably above about 10% wt., and most preferably above about30% wt. Generally, a higher weight percent of unsaturation compounds isused, say, above about 50% wt, and most conveniently the weight percentof the unsaturated hydrocarbons is 100% wt (undiluted form and onlyunsaturated oxygen-containing hydrocarbon and/or olefins). For example,when the catalyst is treated with olefins and oxygen-containinghydrocarbons, the unsaturation may be provided from olefin alone usingsaturated oxygen-containing hydrocarbons or from olefin and someunsaturated oxygen-containing hydrocarbon. Of course, unsaturatedoxygen-containing hydrocarbon alone without olefins can be used for theinventive process. It is understood that the oxygen-containinghydrocarbons may be provided as oxygen-containing hydrocarbon precursorswhich are converted to the oxygen-containing hydrocarbon before or uponreaching the reaction temperature such as, for example, reacting lowermolecular weight aicds (e.g. lower than C₁₂ acids) with glycerol to forma higher triglyceride acid ester within the scope of the invention.

The minimum amounts of oxygen-containing hydrocarbons to be used shouldbe such that upon contact with the catalyst, a catalyst is obtained thatis less spontaneously combustible. The maximum amounts ofoxygen-containing hydrocarbon used are determined primarily byeconomics. In a preferred embodiment the amount of substance or mixtures("mixture(s)" can be a single compound or more than one compounds orcomponents) containing the oxygen-containing hydrocarbon is used thatwill just fill the pore volume of the sulfur impregnated catalyst orjust slightly less, down to about 50 percent, preferably down to about70 percent of the pore volume. A preferred target range is from about 80to about 95 percent of the pore volume. In this manner, the treatedcatalyst will be "dry" and is more convenient to handle.

The presulfurized catalysts obtained by the presulfurization processesof the above embodiment contain at least one presulfidable metal ormetal oxide as defined above and elemental sulfur and/or a sulfurcompound where the catalyst is coated with an oxygen-containinghydrocarbon having at least 12 carbon atoms.

The presulfurized catalyst obtained by the above presulfurizationprocess may be converted to sulfided catalysts by contact with hydrogenat temperatures greater than about 200° C., preferably ranging fromabout 200° C. to about 425° C. Times can run from about 0.5 hours to upto 3 days.

In preferred operation the presulfurized catalyst of the instantinvention is loaded into a hydrotreating and/or hydrocracking reactor ortail gas reactor and hydrogen flow is started to the reactor and thereactor is heated up to operating (hydrotreating and/or hydrocracking ortail gas treating) conditions. In the presence of hydrogen, activationof the catalyst takes place. That is, the metal oxides and hydrogenreact with substantially all of the sulfur incorporated into thecatalyst pores, thus producing hydrogen sulfide, water and metalsulfides. In the hydrotreating and/or hydrocracking process, ahydrocarbon feedstock flow may be started simultaneously with thehydrogen or later.

The process of the present invention is further applicable to thesulfurizing of spent catalysts which have been oxy-regenerated. After aconventional oxy-regeneration process, an oxy-regenerated catalyst maybe presulfurized as would fresh catalyst in the manner set forth aboveand specifically in a manner set forth by way of the following examples.

The instant invention is also intended to encompass a method forstabilizing (less spontaneouly combustible or reducing the self-heatingcharacteristics) a supported metal catalyst containing elemental sulfur,particularly a Group VIB and/or Group VIII metal catalyst, by contactingthe catalyst with an oxygen-containing hydrocarbon at a temperature andtime sufficient to impregnate and/or to react with the catalyst.

In applying the oxygen-containing hydrocarbon to the catalyst, theoxygen-containing hydrocarbon can be added in batches and mixed or addedcontinuously by spraying the catalyst with the oxygen-containinghydrocarbon.

The inventive process is particularly suitable for application tohydrotreating and/or hydrocracking or tail gas treating catalysts. Thesecatalysts typically comprise Group VIB and/or Group VIII metalssupported on porous supports such as alumina, silica, silica-alumina,zeolite and the like. The materials are well defined in the art and canbe prepared by techniques described therein, such as in U.S. Pat. Nos.4,530,911, 4,520,128 and 4,584,287, which are herein incorporated byreference. Preferred hydrotreating and/or hydrocracking or tail gastreating catalysts will contain a group VIB metal selected frommolybdenum, tungsten and mixtures thereof and a Group VIII metalselected from nickel, cobalt and mixtures thereof supported on alumina.Versatile hydrotreating and/or hydrocracking catalysts which show goodactivity under various reactor conditions are alumina-supportednickel-molybdenum and cobalt-molybdenum catalysts and zeolite-supportednickel-molybdenum and nickel-tungsten catalysts. Phosphorous issometimes added as a promoter. A versatile tail gas treating catalystwhich shows good activity under various reactor conditions is analumina-supported cobalt-molybdenum catalyst.

Hydrotreating catalysts which are specifically designed forhydrodenitrification operations, such as alumina-supportednickel-molybdenum catalysts, presulfurized or presulfided by the methodsdescribed herein have equal activities, particularlyhydrodenitrification activities, than catalysts without theoxygen-containing hydrocarbon treatment. Hydrocracking catalysts such asnickel-molybdenum or nickel-tungsten on a zeolite or silica-aluminasupport presulfurized by the methods described herein have increasedliquid yield than catalysts without the oxygen-containing hydrocarbontreatment. Thus, the invention is also an improved hydrotreating and/orhydrocracking process which comprises contacting at hydrotreating and/orhydrocracking conditions a hydrocarbon feedstock and hydrogen with acatalyst which has been presulfurized according to the methods taughtherein and which has been heated to hydrotreating and/or hydrocrackingtemperature in the presence of hydrogen and optionally a hydrocarbonfeedstock. The ability to avoid instantaneous combusting provides theinstant presulfurized catalysts with a significant commercial advantage.

The ex-situ presulfurization method of this invention allows thehydrotreating, hydrocracking and/or tail gas treating reactors to bestarted up more quickly compared with the in-situ operation byeliminating the presulfiding step. Further, the presulfurized catalystsof the invention have a more convenient way of handling the catalysttransported to the plant or reactor site than the conventional ex-situpresulfurized catalysts. Thus, the instant invention relates to animproved process for starting up a hydrotreating and/or hydrocrackingreactor, which comprises loading the catalyst presulfurized according tothe methods described herein into the reactor and activating thecatalyst by heating the reactor to operating conditions in the presenceof hydrogen and optionally a hydrocarbon feedstock. Further, it has beenfound that catalysts activated by heating the catalyst in the presenceof hydrogen and at least one feedstock or hydrocarbon having a boilingpoint of above about 35° C., preferably from about 40° C., morepreferably from about 85° C., to about 700° C., preferably to about 500°C. at atmospheric pressure, give increase yields compared to gasactivated catalysts. Such hydrocarbons include for example jet fuels,kerosines, diesel fuels, gasolines, gas oils, residual gas oils andhydrocarbon feed streams (feedstocks). The catalysts are activated at atemperature within the range from about 25° C. to about 500° C.,preferably to about 450° C. and a hydrogen pressure of from about 50,preferably 350 to about 3000 psig. The hydrocarbon rate will typicallyhave a liquid hourly space velocity ("LHSV") ranging from about 0.1,preferably from about 0.2, to about 20, preferably 15, more preferably10 hr⁻¹. The amount of hydrocarbon is in an amount sufficient to givethe desired LHSV value.

Hydrotreating conditions comprise temperatures ranging from about 100°C. to about 450° C., preferably to about 425° C., and pressures above 40atmospheres. The total pressure will typically range from about 400 toabout 2500 psig. The hydrogen partial pressure will typically range fromabout 200 to about 2200 psig. The hydrogen feed rate will typicallyrange from about 200 to about 10000 standard cubic feet per barrel("SCF/BBL"). The feedstock rate will typically have a liquid hourlyspace velocity ("LHSV") ranging from 0.1 to about 15.

Hydrocracking conditions comprise temperatures ranging from about 100°C., preferably from about 150° C., more preferably from about 200° C.,to about 500° C., preferably to about 485° C., more preferably to about450° C., and pressures above about 40 atmospheres. The total pressurewill typically range from about 100 to about 3500 psig. The hydrogenpartial pressure will typically range from about 100, preferably fromabout 300, more preferably from about 600 psig, to about 3500,preferably to about 3000 psig. The hydrogen feed rate will typicallyrange from about 1000, more preferably from about 2000, to about 15,000,more preferably to about 10,000 standard cubic feet per barrel("SCF/BBL"). The feedstock rate will typically have a liquid hourlyspace velocity ("LHSV") ranging from about 0.05, preferably from about0.1 to about 20, preferably to about 15, more preferably to about 10.First stage hydrocrackers, which carry out considerable hydrotreating ofthe feedstock may operate at higher temperatures than hydrotreaters andat lower temperatures than second stage hydrocrackers.

Tail gas treatment reactors typically operate at temperatures rangingfrom about 100° C., preferably from about 200° C., to about 450° C.,preferably 400° C. and at atmospheric pressure. About 0.5-5% vol. of thetail gas fed to the reactor will comprise hydrogen. Standard gaseoushourly space velocities of the tail gas through the reactor will rangefrom about 500 to about 10,000 hr⁻¹. There are several ways the subjectcatalysts can be started up in a tail gas treatment reactor. Claus unitfeed or tail gas can be used to start up the subject catalysts.Supplemental hydrogen, as required, may be provided by a gas burneroperating at a substoichiometric ratio in order to produce hydrogen.

In another embodiment of the invention, catalysts in a refining or achemical plant reactor such as, for example, hydrocracking,hydrotreating, tail gas treating, hydrogenation, dehydrogenationisomerization and de-waxing can be contacted (treated) with theoxygen-containing hydrocarbons described above and optionally carrieroil including feed oil and/or fused-ring aromatic hydrocarbons beforeunloading from the reactor. The inventive process provides a method ofsafely unloading the catalysts with minimal catalyst oxidation anddeterioration. The oxygen-containing hydrocarbon-containing mixture(mixture can be undiluted oxygen-containing hydrocarbon) penetrates tothe surface of the catalyst and diffuses into the pores of the catalystsat the temperature in the reactor after suspension (or stopping) of itsoperation, and coats the catalyst with a film. The term "coats","coating" and "coated" may be defined in a same manner as "coated"defined above. Typically the operation of the reactor is suspended,stopped or halted by terminating the refining or chemical reaction, forexample by terminating the feed or by lower temperature.

It is preferred that the temperature within the reactor column be lowerthan the smoke point or boiling point (at the reactor operationpressure) of the oxygen-containing hydrocarbon when the mixture is addedto the catalyst in the reactor. Thus, after the operation of the reactoris stopped, the feed and/or catalyst can be cooled from the operatingtemperature by allowing the reactor to equilibrate with the ambienttemperature, recycling or by passing feed through a cooling unit. Thefeed to the reactor can optionally be shut off. For application of manyof the oxygen-containing hydrocarbons, the temperature of the reactorand/or catalyst is preferably less than about 175° C., more preferablyless than about 125° C. when the oxygen-containing hydrocarbon iscontacted with the catalyst at atmospheric pressure. If theoxygen-containing hydrocarbon mixture is contacted with the catalyst atelevated reactor pressures, the reactor and/or catalyst temperatures canbe higher. The contact temperature can be as low as the unloadingtemperature or lower. The catalyst is typically unloaded at atemperature within the range of about room temperature to about 70° C.

The oxygen-containing hydrocarbon mixture is introduced into a reactorcolumn after suspension of reactor operation. The oxygen-containinghydrocarbon mixture can be added to a batch containing the catalysts orto a recycle stream. Optionally, heavy oil or any similar raw materialsfrom the reactor columns can be removed before adding theoxygen-containing hydrocarbon. The catalyst is coated with theoxygen-containing hydrocarbon upon contact and incorporation, thusenhancing the safety of the unloading operation by protecting thecatalyst against oxidation and rendering the catalyst less spontaneouslycombustible.

A mixture containing the oxygen-containing hydrocarbon preferably in anamount from about 1 weight percent to 100 weight percent of the mixtureis contacted with the catalyst in the reactor for a time effective tocoat the catalyst and reduce the self-heating characteristics of thecatalyst. Preferably the mixture should be used in an amount sufficientto coat the surface of the catalyst.

The oxygen-containing hydrocarbon may be apliced in admixture withfused-ring aromatic hydrocarbons and/or a carrier oil. Preferablefused-ring aromatic hydrocarbon includes for example, any fused-ringaromatic hydrocarbons containing at least 2 rings, preferably 2 to 4rings. Examples of the fused-ring aromatic hydrocarbons includesnaphthalenes such as alkylnaphthalene; anthracenes such asalkylanthracene; and pyrenes such as allylpyrene. Such fused-ringaromatic hydrocarbons may be unsubstituted or substituted for examplewith alkyl or aryl moieties. Carrier oil can be any hydrocarbon streamin refining operations or a blend thereof having a flash point of aboveabout 38° C. Preferably carrier oil includes straight-run heavy gas oil(HGO), vacuum gas oil (VGO), diesel and the likes.

The oxygen-containing hydrocarbon and optionally fused-ring aromatichydrocarbon and/or carrier oil can be added through separate lines thenmixed or added after being mixed. If desired, the mixture can be heatedwith any heating means such as for example, heating furnace, bandheater, heating coil or a heat exchanger to the desired temperature.

The ranges and limitations provided in the instant specification andclaims are those which are believed to particularly point out anddistinctly claim the instant invention. It is, however, understood thatother ranges and limitations that perform substantially the samefunction in substantially the same way to obtain the same orsubstantially the same result are intended to be within the scope of theinstant invention as defined by the instant specification and claims.

Illustrative Embodiments

The invention will be described by the following examples which areprovided for illustrative purposes and are not to be construed aslimiting the invention.

EXAMPLE I

This example demonstrates one of the embodiments of the invention wherethe catalysts are first presulfurized and then treated withoxygen-containing hydrocarbons. The onset temperatures of the exothermsof the catalysts of the invention are compared with comparativeexamples.

Part A: Sulfur impregnation

A commercial hydrotreating catalyst having the properties listed belowwas used to prepare the sulfurized catalysts.

                  TABLE 1                                                         ______________________________________                                        Catalyst Properties                                                           ______________________________________                                        Nickel                3.0%    wt                                              Molybdenum            13.0%   wt                                              Phosphorous           3.5%    wt                                              Support          gamma alumina                                                Surface Area, m.sup.2 /g                                                                       162                                                          Water Pore Vol., cc/g                                                                          0.47                                                         Size             1/16 inch trilobes                                           ______________________________________                                    

Typically a 250 gram sample of the above sample was dried at 371° C. forone hour and then cooled to ambient under vacuum. The sample was thenplaced in a flask and enough sulfur, in powdered form, was added at 85°C. to produce a sulfur level of about 10% by weight. The sulfur wasallowed to coat the catalyst then the flask, which was provided with aslow nitrogen purge and placed in a heating mantle, was further heatedto 120° C. for 30 minutes. During this time period the flask wasvibrated continually to provide mixing of sulfur and catalyst. The finalsulfur level was about 10% by weight of the total catalyst. The waterpore volume of the sulfur-impregnated catalyst was determined to beabout 0.37 cc/g

Part B: Oxygen-containing Hydrocarbon Reaction and Comparative Examples

The sulfur-impregnated catalyst from Part A was impregnated with thevarious oxygen-containing hydrocarbons listed in Table 2. Catalyst fromPart A was also impregnated with Diesel and Neodene® 14/16/18alpha-olefins as comparative examples. The catalyst was impregnated withhydrocarbons listed in Table 2 sufficient to fill 80% of the pore volumecalculated by: (pore volume of catalyst from Part A) (80%) (adjustedweight of catalyst)(density of oxygen-containing hydrocarbon orcomparative compounds)=grams of oxygen-containing hydrocarbon orcomparative compounds. The pore volume of the catalyst was determinedwith water (mL/g). Adjusted weight is the amount of sulfur/catalystremaining after retains and pore volume analysis.

The lard, vegetable residue and coconut oil, being solids or semi-solidsat room temperature, were heated up to approximately 80° C. before beingapplied to the catalyst. All other hydrocarbons were simply added to thecatalyst at room temperature. The catalyst was shaken with thehydrocarbon until the catalyst appeared dry and is free flowing. Thistook approximately 10 minutes per sample. Once the hydrocarbon isabsorbed the catalyst temperature was allowed to return to roomtemperature.

150 Grams of the hydrocarbon-containing catalyst were loaded into a 1liter four-neck flask equipped with a thermocouple through one of thenecks and placed in a heating mantle. Another neck of the flask wastubed to a another flask equipped with a condenser which was tubed to asilicone oil-filled container to prevent air back-diffusion (outlet).Nitrogen flow was established to the flask through another neck of theflask (inlet) at 273 cc/min. The remaining neck was stoppered. The flaskattached to a vibratory table and vibrated for the duration of the heattreatment described below.

The reactor was heated to 260° C. over the course of ten to twentyminutes and held there typically for 30 minutes. After heat treatmentwas complete, the reactor contents were cooled to room temperature undernitrogen purge. The samples were analyzed for sulfur content and theexothermic onset temperatures of the samples were tested.

Part C: Self-Heating Ramp Test

Approximately a 12 gram aliquot of the test sample was placed in a 3.1cm diameter, 4.6 cm height sample container. The sample container wasmade of 250 mesh stainless steel net. The sample container was coveredwith a 30 mesh stainless steel net container cover which had a squarebottom net with the corners bent to form four legs as to raise thesample container 0.8 cm off platform.

The sample container was placed in a programmable furnace at ambienttemperature with a stagnant atmosphere. A thermocouple is placed in thecenter of the sample. Another thermocouple is placed near the samplecontainer to monitor oven temperature. The oven was ramped at 0.4°C./minute to 450° C. The temperature data was collected and plotted asdescribed below.

A time-temperature profile was plotted with temperature in the Y-axisand time in the X-axis for catalyst temperature and oven temperature.

Exothermic onset temperatures of the temperature profile test weredetermined by drawing a 45 degree tangent on the sample's temperaturetrace at the onset of an exotherm. From the tangent point, a verticalline was drawn to the oven trace then from that point horizontal to theY axis for temperature readings. The results of the self-heating ramptests are shown in Table 2 below.

                  TABLE 2                                                         ______________________________________                                        Exothermic Onset Temperatures                                                 Oxygen-containing hydrocarbon                                                                   Onset of Exotherm (° C.)                             ______________________________________                                        Lard .sup.a)      262                                                         Vegetable Residue .sup.b)                                                                       250                                                         Distilled Methyl Esters .sup.c)                                                                 206                                                         Linoleic Acid .sup.d)                                                                           244                                                         Fatty alcohol .sup.e)                                                                           212                                                         Linseed Oil .sup.f)                                                                             273                                                         Soybean Oil .sup.g)                                                                             237                                                         Coconut Oil .sup.h)                                                                             200                                                         Comparative                                                                   Diesel .sup.i)    156                                                         Neodene ® 14/16/18 .sup.j)                                                                  158                                                         ______________________________________                                         .sup.a) Lard from Armour Foods.                                               .sup.b) A vegetable oil residue from Arista Industries, Inc. whose            composition is a mixture of glycerides, polyglycerides, polyglycerols,        dimer acids, hydrocarbon and alcohols comprising 79% wt C.sub.18 fatty        acids, and 17% wt C.sub.16fatty acids and having an iodine value of           95-110.                                                                       .sup.c) Distilled methyl esters from Arista Industries, Inc. having 100%      wt of composition of CAS Registry No. 6899052-3.                              .sup.d) 99% purity linoleic Acid from Aldrich Chemical.                       .sup.e) Mixture of saturated and unsaturated alcohol from Henkel              Corporation whose composition is 87-95% wt oleyl alcohol and 2-10% wt         cetyl alcohol having 90-95 iodine value.                                      .sup.f) Raw linseed oil from Anlor Oil Company.                               .sup.g) RBD soybean oil from Lou Ana Foods.                                   .sup.h) Laxmi Brand distributed by House of Spices.                           .sup.i) No. 2 fuel oil with cetane value of 43 from Exxon Refining and        Marketing Company.                                                            .sup.j) An olefin product manufactured by Shell Chemical Co. whose            composition is 93.5% wt. minimum alphamonoolefin comprising 15% wt.           C.sub.14 alphamonoolefin, 50% wt. C.sub.16 alphamonoolefin and 35% wt.        C.sub.18 alphamonoolefin.                                                

Part D: Sulfur Leaching Tests

Toluene was used as a extractive solvent for measuring the ability ofthe catalysts to resist sulfur leaching. This method is applicable tosolid materials such as heterogeneous catalysts. For testing othermaterials modifications to this procedure may be required beforeanalysis. Generally, the samples are subjected to a hot tolueneextraction over a period of time, then washed with petroleum ether anddried for analysis. Sulfur analyses before and following the extractionare used to calculate percent sulfur retention. A thorough drying of thesample is necessary to prevent artificially high carbon and sulfurreadings during analysis.

A Soxhlet extractor (200 ml) equipped with a boiling flask (500ml) andAllihn condenser was used in this test. The cotton thimble of theextractor was filled with approximately 10 grams of catalyst to beanalyzed and loaded into the Soxhlet extractor. The boiling flask wasfilled about 3/4 full (about 350 ml) with toluene. Toluene was broughtto rapid boiling so a cycle of filling and emptying of thimble occursapproximately every 7-9 minutes. The catalyst sample was extracted for aminimum of 4 hours to a maximum of 18 hours. Extraction was stopped whenextract in siphon tube was water clear. Catalyst was cooled and placedon a filter in Buchner funnel and washed with 50 mL of petroleum etherto displace toluene then dried in a 100° C. oven for 1 hour. Prolongeddrying may compromise results by loss of sulfur from sample. Analternate drying method is to purge the sample with nitrogen for 2 to 3hours. The extracted catalysts were analyzed for carbon and sulfurcontent (Carbon wt. % and Sulfur wt. % respectively) with a LECOcorporation CS-244 carbon-sulfur analyzer. The percent of sulfurretained after extraction is shown in Table 3 below. This percent ofretained sulfur is calculated as the amount of sulfur on the catalystafter the extraction of Part D (Fresh Basis after) divided by the sulfurin the catalyst after the oxygen-containing hydrocarbon treatment ofPart B (Fresh Basis before) times 100%. Fresh basis was calculated usingthe following equation:

    Fresh Basis Sulfur=Sulfur wt. %/(100-(Carbon wt. % +Sulfur wt. %))*100%.

                  TABLE 3                                                         ______________________________________                                        Sulfur Leaching Results                                                       "Reactant" Hydrocarbon                                                        Amount of Sulfur After Extraction                                             Oxygen-containing hydrocarbon                                                                   Sulfur Extractability (%)                                   ______________________________________                                        Lard .sup.a)      >95                                                         Vegetable Residue .sup.b)                                                                       85                                                          Distilled Methyl Esters .sup.c)                                                                 >95                                                         Linoleic Acid .sup.d)                                                                           86                                                          Fatty alcohol .sup.e)                                                                           66                                                          Linseed Oil .sup.f)                                                                             85                                                          Soybean Oil .sup.g)                                                                             88                                                          Coconut Oil .sup.h)                                                                             96                                                          Comparative                                                                   Diesel .sup.i)    77                                                          Neodene ® 14/16/18 .sup.j)                                                                  95                                                          ______________________________________                                         .sup.a) -.sup.j) as described in Table 2.                                

Part E: Sulfur Retention Tests

A commercial hydrotreating catalyst having the properties listed belowwas used to prepare the sulfurized catalysts for this test:

                  TABLE 4                                                         ______________________________________                                        Catalyst Properties                                                           ______________________________________                                        Nickel                2.24%   wt                                              Molybdenum            7.54%   wt                                              Phosphorous           3.5%    wt                                              Support          gamma alumina                                                Surface Area, m.sup.2 /g                                                                       309                                                          Water Pore Vol., cc/g                                                                          1                                                            Size             1/16 inch trilobes                                           ______________________________________                                    

Sulfur was impregnated according to the method of Part A using 5.9wt %of sulfur and soybean oil and Neodene® 14/16/18 were impregnatedaccording to the method of Part B. Carbon and sulfur content of thecatalyst were analyzed using LECO corporation CS-244 carbon-sulfuranalyzer. Fresh Basis Sulfur was calculated using the equation shown inPart D. Percent Stoichiometric sulfur was calculated by dividing (theFresh Basis Sulfur) over (the amount of sulfur added) times 100 percent.

                  TABLE 5                                                         ______________________________________                                        Sulfur Retention                                                                      Carbon    Sulfur  Fresh Basis                                                                             Percent                                   Sample  wt. %     wt. %   Sulfur wt. %                                                                            Stoichiometric                            ______________________________________                                        Neodene ®.sup.a)                                                                  26.7      3.0     4.3       73                                        Soybean.sup.b)                                                                        33.5      3.5     5.6       95                                        ______________________________________                                         .sup.a) and .sup.b) as described in Table 2 as .sup.j) and .sup.g)            respectively.                                                            

As can be seen from the Table. the percent retention of sulfur issignificantly improved by using a glyceride fatty acid ester.

EXAMPLE II

This example demonstrates the embodiment where the presulfided orsulfurized catalyst is coated with oxygen-containing hydrocarbons. Thisis a post-coating method. A commercial sulfurized hydrotreating catalysthaving the properties listed below was used to prepare the sulfurizedcatalysts.

                  TABLE 6                                                         ______________________________________                                        Catalyst Properties                                                           ______________________________________                                        Nickel               3.0%    wt                                               Molybdenum           13.0%   wt                                               Phosphorous          3.5%    wt                                               Sulfur               8%      wt                                               Support       gamma alumina                                                   Size          1/16 inch trilobes                                              ______________________________________                                    

The oxygen-containing hydrocarbon listed in Table 7 below were added tothe sulfurized catalyst in an amount listed in Table 7. Theoxygen-containing hydrocarbon was added to the catalyst at ambienttemperature and allowed to absorb into the pores. The treated catalystmay take some time to absorb the substances so that it is not tacky andflows freely. The self-heating ramp test was measured in a similarmanner to Example I, part C.

                  TABLE 7                                                         ______________________________________                                        Post-coating                                                                                  Amount                                                        Oxygen-containing Hydrocarbon                                                                 (wt %)    Onset of Exotherm (° C.)                     ______________________________________                                        1:1 wt ratio soybean:linseed                                                                  8         280                                                 1:3 wt ratio soybean:linseed                                                                  10        260                                                 ______________________________________                                    

EXAMPLE III

The presulfurized catalyst prepared according to the inventive method ina similar manner to Example I was used in a hydrotreating process.

7 types of catalysts, 1 comparative and 6 of this invention, were usedto demonstrate the advantages of the instant invention as applied to ahydrotreating process. These were:

1) COMP Catalyst--This is the commercial hydrotreating catalyst listedin Table 1 which has been sulfided by an industry accepted sulfidingmethod using hydrogen and hydrogen sulfide as is described below.

2) A Catalyst--This is a catalyst prepared as described in IllustrativeEmbodiment I with 100% stoichiometric sulfur and using the larddescribed in Table 2 as the treating oxygen-containing hydrocarbon.

3) B Catalyst--This is a catalyst prepared as described in IllustrativeEmbodiment I with 100% stoichiometric sulfur and using the vegetableresidue described in Table 2 as the treating oxygen-containinghydrocarbon.

4) C Catalyst--This is a catalyst prepared as described in IllustrativeEmbodiment I with 100% stoichiometric sulfur and using the coconut oildescribed in Table in Table 2 as the treating oxygen-containinghydrocarbon.

5) D Catalyst--This is a catalyst prepared as described in IllustrativeEmbodiment I with 100% stoichiometric sulfur and using the methyl estersdescribed in Table 2 as the treating oxygen-containing hydrocarbon.

6) E Catalyst--This is a catalyst prepared as described in IllustrativeEmbodiment I with 100% stoichiometric sulfur and using the vegetable oildescribed in Table 2 as the treating oxygen-containing hydrocarbon andNeodene® 14/16/18 alpha-olefin described in Table 2 in a weight ratio of1:1.

The catalysts were loaded into the reactor as follows: 48 cc of catalyst(basis compacted bulk density) was divided into 3 aliquots. The firstaliquot contained 4 cc of catalyst and was diluted with 10 to 14 meshalundum at a ratio of alundum to catalyst of 10:1. The remaining twoaliquots contained 22 cc of catalyst each and were diluted 1:1 withalundum. These aliquots were loaded into the reactor tube with thedilute one on top (the inlet end).

Activity Tests

A blend of 50 wt % vacuum gas oil, 25 wt % light cycle oil and 25 wt %CC heavy gas oil (VGO/LCO) was used as feedstock and had the followingproperties:

    ______________________________________                                        % wt Sulfur    1.93                                                           ppm Nitrogen   1420                                                           Refractive Index                                                                             1.5377 (25° C.)                                         API Gravity    17.8°                                                   ______________________________________                                    

1) COMP Catalyst Activation

The COMP Catalyst was dried at 400° C. for one hour in air, cooled in adesiccator and loaded into the reactor. It was sulfided in a flow of 60Nl/hr of 95% vol hydrogen/5%vol hydrogen sulfide according to thefollowing schedule:

a. ambient to 218° C. in one hour

b. hold at 218° C. for one hour

c. heat from 218° C. to 329° C. in one hour

d. heat from 229° C. to 343° C. in one hour

e. hold at 343° C. for one hour

f. cool reactor and hold at 246° C.

2) Diesel Activation

This method was used to activate catalysts of this invention using adiesel refined for cars and trucks and was as follows:

a. Unit was pressurized to 700 psig and hydrogen circulation wasestablished at 1000 SCF/BBL (N1/hr).

b. Diesel feed was started to the catalyst bed at 1.5 LHSV and ambienttemperature.

c. The reactor temperature was raised to 121° C. in one hour, thenincreased to 343° C. at rate of 27.8° C./hour. Temperatures were held at343° C. for 30 minutes.

d. The reactor was then cooled over 2 hours to 246° C.

3) Activity Testing

For activity testing the unit was pressured up to 700 psig and heated to246° C. with a hydrogen gas rate of 220 SCF/bbl (13.2 N1/hr). TheVGO/LCO feed was started to the unit at 1.5 LHSV (66 gm/hr). After thefeed had wetted the entire bed (and product was noted in the separator),the temperature was raised to 329° C. at 22.2° C./hr.

After the reactor was at 329° C., a 12 hour break-in period was begun.The product from this period was not analyzed. The run was continuedwith additional weight periods of 12 hours and the products of thirdweight period (37-48 hours) were analyzed for nitrogen and sulfur. Fromthese values rate constants were calculated for the hydrodenitrification("HDN") reaction and the hydrodesulfurization ("HDS") reaction. Rateconstants provide an indication of how active the catalyst is, thehigher the rate constant, the faster the reaction process, and thehigher the conversion of sulfur and nitrogen at a given space velocity(feed rate). For HDN the reaction order is 1.0 and the k value iscalculated by the equation ##EQU1## For HDS the reaction is not firstorder and many values are used, but 1.7 is the value most used and isused herein to calculate as follows: ##EQU2## The relative rateconstants are provided in Table 8. The have been normalized against thevalues for the third weight period for the COMP Catalyst.

                  TABLE 8                                                         ______________________________________                                        Activity Tests                                                                Weight Period                                                                 Catalyst                                                                             Activation                                                                              HDS Rel. K Value                                                                             HDN Rel. K Value                              ______________________________________                                        COMP   1) Standard                                                                             1.00           1.00                                          A      2) Diesel 0.94           0.88                                          B      2) Diesel 1.04           0.94                                          C      2) Diesel 0.87           0.87                                          D      2) Diesel 0.94           1.02                                          E      2) Diesel 1.00           1.01                                          ______________________________________                                    

As can be seen from the above table the catalysts of this invention showa comparable hydrodenitrification activity (without significant decreasein activity) to a traditional hydrotreating catalyst. Further, catalystscontaining unsaturated hydrocarbons show advantage over catalyst withonly saturated hydrocarbons with regard to the hydrodenitrificationactivity.

EXAMPLE IV

Z-753 Ni-W/Ultrastable Y zeolite based hydrocracking catalyst, (fromZeolyst International Inc.), was presulfurized according to theprocedure outlined in Example I.

Sulfur was incorporated according to the method of Part A using 5.5 wt %of sulfur. Soybean oil and Neodene were impregnated on the catalystaccording to the method of Part B. Carbon and sulfur content of thecatalyst were analyzed using LECO corporation CS-244 carbon-sulfuranalyzer. Fresh Basis Sulfur was calculated using the equation shown inPart D. Percent Stoichiometric sulfur was calculated by dividing theFresh Basis Sulfur percent by the percent sulfur calculated for completeconversion of the oxidic nickel and tungsten to the corresponding Ni₃ S₂and WS₂ phases.

                  TABLE 10                                                        ______________________________________                                        Sulfur Retention                                                                      Carbon    Sulfur  Fresh Basis                                                                             Percent                                   Sample  wt. %     wt. %   Sulfur wt. %                                                                            Stoichiometric                            ______________________________________                                        Neodene ®.sup.a)                                                                  11.1      1.4     1.6       43                                        Soybean.sup.b)                                                                        20.5      2.4     3.1       84                                        ______________________________________                                         .sup.a) as described in Table 2 as .sup.j)                                    .sup.b) as described in Table 2 as .sup.g)                               

As can be seen from Table 10, the percent retention of sulfur issignificantly improved by using a glyceride fatty acid ester such assoybean oil.

Performance Tests

A blend of 75 vol % hydrotreated cracked heavy gas oil, and 25 vol %hydrocracker bottoms stream was used as feedstock for performancetesting of the zeolitic hydrocracking catalysts obtained from Example IVabove and the fresh Z-753 (Reference Catalyst). Some of the feedstockproperties are listed in Table 11. DMDS and n-amylamine were added tothe feedstock to generate the requisite levels of H₂ S and NH₃,respectively.

                  TABLE 11                                                        ______________________________________                                        Performance Testing Feedstock Properties                                      ______________________________________                                        ppm Sulfur       14                                                           ppm Nitrogen     25                                                           wt % Carbon      87.334                                                       wt % Hydrogen    12.69                                                        API Gravity      26.1°                                                 338+ ° C. (wt %)                                                                        71.4                                                         DMDS (wt %)      0.133                                                        n-amylamine (wt %)                                                                             0.079                                                        ______________________________________                                        Simulated Distillation of Feedstock                                                  WT %  TEMP ° C.                                                 ______________________________________                                               IBP   181                                                                     5%    248                                                                     25%   330                                                                     50%   382                                                                     75%   434                                                                     90%   481                                                                     98%   537                                                                     FBP   572                                                              ______________________________________                                    

Performance Testing Conditions

The conditions employed for the performance testing of the zeoliticcatalysts above are given in Table 12.

                  TABLE 12                                                        ______________________________________                                        Performance Testing Conditions                                                ______________________________________                                        Hydrogen Pressure (psig)                                                                             1800                                                   Hydrogen Circulation (scf H.sub.2 /bbl feed)                                                         8935                                                   LHSV (hr.sup.-1)       1.5                                                    Cut Point for converison calculation (° C.)                                                   338°                                            Conversion Target (Single Pass, wt %)                                                                80.0                                                   ______________________________________                                    

Catalyst Activation Procedures

1) Zeolite Reference Catalyst: Gas Phase Activation

The fresh Z-753 catalyst was dried at 482° C. for one hour in air,cooled in a desiccator and loaded into the reactor. It was sulfided in aflow of 95% vol hydrogen/5% vol hydrogen sulfide at a GHSV of 1500 hr⁻¹,according to the following gas phase schedule:

a. ambient to 149° C., hold 1 hour

a. 149° C. to 371° C. in six hours

b. hold at 371° C. for two hours

c. cool reactor to 149° C. and hold

d. switch to pure hydrogen flow

1b) Zeolite Reference Catalyst: Liquid Phase Activation

This method was used to activate the reference zeolite catalystmentioned above. After loading the dried catalyst, the reactor wasbrought to 1800 psig pure hydrogen, at a circulation rate of 8935 scfhydrogen/bbl feed. The activation feedstock employed consisted of theperformance testing feedstock containing sufficient dimethyldisulfide(DMDS) to produce 2.5 vol % H₂ S, and n-amylamine to produce 150 ppm NH₃in the gas phase, respectively. The procedure for the activation of thereference catalyst was as follows:

a. reactor brought to operating pressure and hydrogen rate

b. activation feedstock introduced at 149° C.

c. 149° C. to 232° C. in 3 hours

d. 232° C. to 302° C. in 18 hours

e. 302° C. to 315° C. in 8 hours

f. hold 315° C. for 8 hours

g. switch to activity testing feedstock and adjust temperature tomaintain 80 wt % conversion of feed.

During this activating procedure (steps c-f), H₂ S and i-butane werecontinuously monitored in the exit gas stream of the reactor.Temperature was ramped as long as H₂ S remained above 2000 ppmv, andisobutane concentration remained below 0.4 vol %. Otherwise, the rampwas discontinued until these levels were realized.

2) Zeolitic Catalyst:

Gas Phase Activation with 5.0% vol H₂ S

The zeolitic hydrocracking catalyst from Example IV was dried at 482° C.for one hour in air, cooled in a desiccator and loaded into the reactor.It was activated in the same manner as the catalyst in case 1) of thisExample.

2a) Zeolitic Catalyst:

Gas Phase Activation with 0.5% vol H₂ S.

After reactor loading 25 cc of the zeolitic hydrocracking catalyst fromExample IV and pressure testing, the following procedure was used for agas phase activation that simulates 0.5% H₂ S in the recycle gas:

a. pressurize reactor to 450 psig with pure H₂ and establish a GHSV of320 hr⁻¹.

b. ramp temperature at 14° C./hr to 120° C.; begin sampling the reactoroff-gas for H₂ S each 0.5 hr.

c. switch to 0.5% H2S/95.5% H₂ mixture

d. ramp temperature to 205° C. at 14° /hr.

e. at 205° C., increase pressure to 1500 psig and establish a GHSV of850 hr⁻¹.

f. ramp temperature to 370° C. at 14° C./hr, interrupt ramp if H₂ S inreactor off-gas drops below 2000 ppmv.

g. hold at 370° for 4 hours

h. cool to 149° C.

i. switch to pure H₂ and set pressure and flow rates for performancetesting

2b) Zeolitic Catalyst: Liquid Feed Activation

The same method mentioned above for reference catalyst liquid activationwas used to activate zeolitic catalyst from Example IV. It uses the sameactivity testing feed mentioned above with sufficient dimethyldisulfide(DMDS) and n-amylamine added to produce 2000 ppm H₂ S and 150 ppm NH₃ inthe gas phase, respectively. DMDS was added to the feed in order tosimulate a minimum level of H₂ S that could be tolerated duringactivation in the gas recycle loop of commercial units.

All gas phase activated catalysts (1), (2), (2a): After activation withthe hydrogen sulfide/hydrogen mixture, the reactor was cooled to 149° C.and the following startup procedure was implemented:

introduce activity testing feed at 149° C.

b. 149° C. to 260° C. in 5 hours

c. 22° C./day for 4 days

d. 5.5° C./day for 5 days

e. adjust reactor temperature to maintain 80 wt % conversion of 338+° C.in feed.

Conversion (wt %) is defined as follows: ##EQU3## In this conversiondefinition, gaseous products are included. Perfromance Testing Results

Liquid and gas product streams were both analyzed and mass balancedyields based on feed oil and hydrogen were calculated. Representativeweight period results from testing of the three zeolite catalysts arefound in Table 13. Values for product cuts are reported as mass balancedwt % based on feed.

                  TABLE 13                                                        ______________________________________                                        Representative performance measures for zeolitic                              hydrocracking catalysts..sup.a Values reported are                            calculated for 80% conversion.                                                ______________________________________                                        PRODUCT CUTS (° C.)                                                    Cata-       C.sub.1 -                                                                            C.sub.5 -                                                  lyst.sup.b                                                                         Temp   C.sub.4                                                                              82°                                                                          82-190°                                                                      190-288°                                                                      288-338°                                                                      338°+                     ______________________________________                                        1    378    15.0   23.0  37.8  9.1    2.7    14.5                             1b   381    17.1   23.5  35.4  8.0    3.3    14.5                             2    378    12.1   18.5  40.6  12.3   3.6    14.5                             2a   381    14.4   19.3  39.7  11.5   3.7    14.4                             2b   377    11.8   19.1  42.0  10.9   3.2    14.5                             ______________________________________                                        Cata-       C.sub.1 -                                                                            C.sub.5 -                                                  lyst.sup.c                                                                         Temp   C.sub.4                                                                              82    82-190                                                                              190-288                                                                              288-338                                                                              338+                             ______________________________________                                        1    384    17.7   25.4  34.9  7.3    2.3    14.6                             2a   387    17.3   22.9  35.1  8.8    3.3    14.5                             2b   381    13.2   19.9  40.9  10.4   2.9    14.5                             ______________________________________                                         .sup.a Absence of a letter following the catalyst reference number denote     gas phase activation with 5% H.sub.2 S/95% H.sub.2, "a" following the         catalyst number denotes gas phase activation with 0.5% H.sub.2 S/99.5%        H.sub.2, and "b" denotes liquid phase activation.                             .sup.b Values reported are for 700 hours on feed.                             .sup.c Values reported are for 1400 hours on feed.                       

As can be seen from Table 13, the zeolitic catalysts of this invention(2,2a,2b) shows a significant improvement in liquid yield relative tothe reference catalysts (1 and 1b). This improvement in yield occursregardless of whether the reference catalyst was activated in liquidphase or gas phase, but the more appropriate comparison of the twoliquid phase activations reveals the greatest advantage for theinvention catalyst. In this case, the catalyst of the invention alsoexhibits an advantage in activity, with a 3° C. lower temperaturerequirement at 80 wt % conversion.

                  TABLE 14                                                        ______________________________________                                        Yield stability data on selected cuts for reference                           and invention catalysts.                                                             C.sub.1 -C.sub.4 Yields                                                                     82-190° C. Yields                                 HOURS ==>                                                                              500     1000    1600  500   1000  1600                               ______________________________________                                        Catalyst                                                                      1        13.8    16.6    18.3  38.6  36.4  34.5                               1b       15.4    19.5    --    37.3  32.8  --                                 2        11.1    14.2    --    41.4  39.0  --                                 2a       11.6    14.8    16.8  40.6  37.8  35.5                               2b       10.1    12.7    13.2  43.0  41.0  40.7                               ______________________________________                                    

Table 14 illustrates the additional benefit of yield stabilityassociated with the process of liquid phase activation of the catalystsprepared according to Example IV. Both the gas phase activated referencecatalyst (1) and the liquid phase activated invention catalyst (2b) havean initial C1-C4 yield decline rate of 5.6 wt %/1000 hrs. However, inthe case of (2b), the yield decline rate between 1000 and 1600 hours onfeed has dropped to 0.8 wt %/1000 hrs, while that of (1) is 2.8 wt%/1000 hrs. The case is even more dramatic when examining the naphtharange (82-190° C.) liquid yields. The 1000-1600 hours yield decline ratefor (1) is 3.2 wt %/1000 hrs, while that of (2b) is only 0.5 wt %/1000hrs. This yield stability can translate into significant improvement inoutput of valuable products for the refiner, at the same time decreasingthe production of the less valuable C1-C4 stream.

EXAMPLE V

This example demonstrates the embodiment where the spontaneouslycombustible or self-heating catalyst is unloaded from a reactor aftertreatment with oxygen-containing hydrocarbons.

A highly self-heating, spent, hydrotreating catalyst listed below(obtained from a hydrotreating reactor) was treated with 1.5 Wt. %soybean oil in a carrier oil (feed stream) and a second sample of samematerial was treated with 100% soybean oil. The mixtures were heated to140° C. under nitrogen for one hour and then cooled and drained. Thematerial was tested for self-heating properties according to Appendix Eof 49 CFR 173 (Test for Class 4, Division 4.2 Substances in Code ofFederal Regulations). Test in 49 CFR 173 requires a 2.5 cm cube sizesample and a 10 cm cube size sample.

The samples were further analyzed for exothermic onset by a DifferentialScanning Calorimetry, Mettler's TA 4000 using a DSC27HP DSC measuringcell. Onset temperatures were determined by application of the DSC'ssoftware. For the purposes of this test the onset and half the distancealong the trace to the first peak were entered to the software tocalculate the onset temperature and slop of the curve. The sample washeated from 30° C. to 500° C. at 10° C. per minute. A 500 cc/min of airpurge the DSC measuring during the test.

    ______________________________________                                        Catalyst properties:                                                          Cobalt/Molybdenum on activated alumina                                        ______________________________________                                               Size         1/20 inch                                                        Shape        Quadralobe                                                       Form         Spent                                                            Carbon       12.9 Wt. %                                                       Sulfur        7.9 Wt. %                                                ______________________________________                                    

Both samples treated with soybean oil (at 1.5 and 100%) passed the LargeBasket Test as described in Appendix E of 49 CFR 173. The untreatedsample failed the Large Basket Test.

Exothermic Onset temperatures for the samples determined by DSC are asfollows:

                  TABLE 15                                                        ______________________________________                                                        Onset Temperature                                                                          Integration*                                     Sample          (° C.)                                                                              (J/g)                                            ______________________________________                                        Untreated Sample                                                                              140          2857.6                                           1.5 Wt. % Soybean Oil                                                                         238          392.2                                            100 Wt. % Soybean Oil                                                                         232          261.0                                            ______________________________________                                         *samples integrated from onset to 500° C.                         

Samples treated with soybean oil have reduced self-heating. The sampletreated with 100% soybean oil have a smaller overall exotherm than the1.5 Wt.% treated sample as shown by the integration values for eachsample.

What is claimed is:
 1. A process for hydrocracking hydrocarbon streamscomprising contacting the streams in the presence of hydrogen with ahydrocracking catalyst containing sulfides of metals of Group VIB and/orGroup VIII of the Periodic Table on a porous support at a temperaturewithin the range of 100° C. to about 500° C., said hydrocrackingcatalyst is prepared by the process comprising treating a presulfurizedcatalyst with a substance comprising at least one oxygen-containinghydrocarbon having at least 20 carbon atoms and have an iodine value ofabove 60 then liquid activating the thus-treated presulfurized catalystby heating the treated presulfurized catalyst in the presence ofhydrogen and at least one hydrocarbon, said hydrocarbon having a boilingpoint of above about 35° C. at atmospheric pressure, said activiation iscarreid out at a temperature within the range of about 25° C. to about430° C., hydrogen partial pressure within the range of about 50 psig toabout 3000 psig and Liquid Hourly Space Velocity of from about 0.1 toabout 20 hr⁻¹ to provide a hydrocracking catalyst.
 2. The process ofclaim 1 wherein the hydrocracking catalyst is a supported metal catalystsupported on at least one zeolite or silica-alumina.
 3. The process ofclaim 2 wherein the streams are contacted with the hydrocrackingcatalyst at a temperature within the range of from about 100° C. to 450°C.
 4. The process of claim 1 wherein the hydrocarbon has a boiling pointof from about 40° C. to about 700° C.
 5. The process of claim 1 whereinthe hydrocarbon has a boiling point of from about 85° C. to about 500°C.
 6. The process of claim 1 wherein the hydrocarbon is selected formthe group consisting of jet fuel, kerosine, diesel fuel, gasoline, gasoil, residual gas oil and hydrocarbon feed streams.
 7. The process ofclaim 1 wherein the activation is carried out in the presence of acompound to produce ammonia.
 8. The process of claim 1 wherein thetreated sulfur-containing catalyst is heated at a temperature of fromabout 175° C. to about 350° C.
 9. A process for hydrocrackinghydrocarbon streams comprising contacting the streams in the presence ofhydrogen with a hydrocracking catalyst containing sulfides of metals ofGroup VIB and/or Group VIII of the Periodic Table on a porous support ata temperature within the range of 100° C. to about 500° C., saidhydrocracking catalyst is prepared by the process comprising coatingand/or impregnating at least a portion of a sulfur-incorporated catalystwith a substance comprising at least one oxygen-containing hydrocarbonhaving at least 20 carbon atoms and have an iodine value of above 60,then liquid activating the thus-produced presulfurized catalyst byheating the treated presulfurized catalyst in the presence of hydrogenand at least one hydrocarbon, said hydrocarbon having a boiling point ofabove about 35° C. at atmospheric pressure, said activiation is carriedout at a temperature within the range of about 25° C. to about 430° C.,hydrogen partial pressure within the range of about 50 psig to about3000 psig and Liquid Hourly Space Velocity of from about 0.1 to about 20hr⁻¹ to provide a hydrocracking catalyst.
 10. The process of claim 9wherein the hydrocracking catalyst is a supported metal catalystsupported on at least one zeolite or silica-alumina.
 11. The process ofclaim 9 wherein the streams are contacted with the hydrocrackingcatalyst at a temperature within the range of from about 100° C. to 450°C.
 12. The process of claim 9 wherein the hydrocarbon has a boilingpoint of from about 40° C. to about 700° C. at atmospheric pressure. 13.The process of claim 9 wherein the hydrocarbon has a boiling point offrom about 85° C. to about 500° C. at atmospheric pressure.
 14. Theprocess of claim 9 herein the hydrocarbon is selected form the groupconsisting of jet fuel, kerosine, diesel fuel, gasoline, gas oil,residual gas oil and hydrocarbon feed streams.
 15. The process of claim9 wherein the activation is carried out in the presence of a compound toproduce ammonia.
 16. The process of claim 9 wherein the treatedsulfur-containing catalyst is heated at a temperature of from about 175°C. to about 350° C.